1. Field of the Invention
This invention relates to heat recovery units. More particularly, this invention relates to heat recovery units that operate thermosyphonically to flow water in a heat exchanging relationship with a source of heat.
2. Description of the Prior Art
Presently there exist many types of heat recovery units designed to operate in combination with a vapor compression heat transfer system such as a heat pump or air conditioner. Basically, heat recovery units operate as a precooler to desuperheat the hot refrigerant gas being discharged by the compressor of the system, and transfer such heat to a fluid such as water. In some applications, the precooler heat exchanger is positioned within a large tank such that the fluid contained therein becomes heated during operation of the compressor. In other applications, a continuous supply of fluid such as water is forced through the precooler heat exchanger to desuperheat the refrigerant passing therethrough. In some, the water flows through a heat exchanger thermosyphonically, but with limited heat exchange due to inadequate consideration of the requirements for optimized heat transfer and efficient fluid flow.
The state of the art is exemplified in my prior U.S. Pat. Nos. 4,599,870 and 7,055,339, and the following patents (and patent application) that were cited in either of them during their respective prosecutions or that have cited either of them after their respective issuances, the disclosures of each of which are each hereby incorporated by reference herein:
5,689,9666,857,2856,311,5614,293,3235,897,3386,871,5464,330,3095,970,7286,874,6944,350,0245,993,2236,351,3904,351,1596,007,4555,417,2014,356,7066,070,4237,234,6464,386,5006,116,0487,363,8194,441,9026,155,1197,726,1514,449,3776,237,3597,726,2636,300,1695,157,9372005/0186703
A major disadvantage to the former types of precoolers is their tendency to uncontrollably heat the fluid and, in the case of water, may produce steam or water that is too hot for use. In the latter applications, a mechanical pump is necessary in order to circulate the fluid through the precooler during operation of the compressor and controls are required to control the operation of the pump to insure adequate temperature control. This necessarily precludes efficient production of hot fluid, in that some energy must be expended to drive the pump mechanism, and some production of heat is lost due to pump controls, limiting operation time of the pump.
Therefore, it is an object of this invention to provide an apparatus and a method which overcomes the aforementioned inadequacies of the prior art devices and provides an improvement which is a significant contribution to the advancement of heat recovery art.
Another object of this invention is to provide a heat recovery unit which optimizes the transfer of heat from a first fluid to a second fluid, by providing a heat exchanger that is a tube-on tube heat exchanger that is wound in a direction that takes advantage of the Coriolis force effect for optimum flow rate, and is wound in a tight radius (diameter) to provide optimized turbulence for optimum heat transfer.
Another object of this invention is to provide a heat recovery unit that minimizes the friction loss pressure drop through the heat exchanger by sizing the refrigerant line size used in the heat exchanger for minimum friction related pressure loss for the maximum sized HVACR system the heat exchanger is attached to, while maintaining an adequate refrigerant velocity to provide for oil flow through the heat exchanger.
Another object of this invention is to provide the optimized location of the heat exchanger of this heat recovery unit that produces an optimized heat transfer, by providing the optimum height of the secondary fluid entry into the heat exchanger above the exit of the secondary fluid from the fluid exit point at the bottom of the secondary fluid storage tank.
Another object of this invention is to provide a heat recovery unit which is operable to transfer heat from a first fluid to a second fluid without the use of mechanical fluid pumps or the like.
Another object of this invention is to provide a heat recovery unit which is adaptable to recover the superheat from a vapor compression heat transfer system such as a heat pump or air conditioner.
Another object of this invention is to provide optimized connector tubing sizes to optimize flow of the refrigerant through said connectors, by sizing the connector tubing to minimize friction related pressure loss while providing a size adequate to insure minimum required refrigerant velocity to maintain proper oil flow through the refrigeration system.
Another object of this invention is to provide the installer with an engineered refrigerant line sizing chart to ensure that the line sizes and heat exchanger installation will produce the least amount of friction pressure loss possible while maintaining adequate refrigerant velocity to maintain good oil return to the compressor.
Another object of this invention is to provide optimized connector tubing sizes to optimize the secondary fluid flow through said connectors, by sizing the connector tubing to maximize the flow through said connectors.
Another object of this invention is to provide a heat recovery unit which is readily adaptable to conventional hot water tanks without alteration of the hot water tank other than removing and/or replacing existing fittings and connectors.
Another object of this invention is to provide a heat recovery unit which includes an anti-scald mixing valve arrangement to limit the temperature of the water being discharged from the tank for subsequent use.
Another object of this invention is to provide a heat recovery unit in which the anti-scald mixing valve assembly, the properly sized fluid (being heated) connectors, the optimizing location mounting component, and the heat exchanger unit are packageable as a kit to be sold to distributors for retail installation.
An additional object of this invention is to provide a method of locating the heat exchanger unit at the optimum location to provide for optimized heat transfer and water (fluid) flow through said heat exchanger.
Another object of this invention is to provide a method for accomplishing the above stated objects of the apparatus of the present invention.
The foregoing has outlined some of the pertinent objects of the invention. These objects should be construed to be merely illustrative of some of the more prominent features and applications of the intended invention. Many other beneficial results can be attained by applying the disclosed invention in a different manner or modifying the invention within the scope of the disclosure. Accordingly, other objects and a fuller understanding of the invention may be had by referring to the summary of the invention and the detailed description of the preferred embodiment in addition to the scope of the invention defined by the claims taken in conjunction with the accompanying drawings.